Middle-class children are far more likely to have drunk alcohol by the age of
12 than those from lower social groups, research has found.

More than one in three of those born in professional households had downed a full glass before reaching their teenage years, the statistics show.

The 35 per cent figure among the middle classes is almost twice the level found among 12-year-olds across all economic groups.

Experts said that most children who had drunk alcohol at such a young age were getting it from their own homes.

While some were secretly raiding well-stocked drinks cabinets, many more were being allowed to drink by parents who believed that it would help them to develop more mature attitudes towards alcohol.

The Ipsos Mori poll for charity Drinkaware, which is funded by the alcohol industry to promote sensible drinking, surveyed more than 500 parents from the social groups ABC1 and their children, aged between 10 and 17.

The findings contrast with NHS figures which show that across all social classes, 19.9 per cent of 12-year-olds have had a full glass of alcohol.

The majority of parents in the Drinkaware study thought it was inevitable that children would drink before they turned 16, while one third thought it was "OK" for them to do so.

Chris Sorek, the charity's chief executive said: "These children who are drinking at the age of 12 are not walking into a pub to buy a pint, and they are not getting alcohol from off-licenses.

"In the main, they are drinking at home, because their parents think teenage drinking is inevitable, and think that this might be the way to introduce it sensitively."

In fact, research had found that children were more likely to develop an alcohol problem if they were not set clear boundaries, he said.

Government advice states that alcohol should never be given to children below the age of 15, but 50 per cent of those surveyed had drunk it by the age of 14.

A crackdown on underage drinking in the seaside down of Newquay found that 70 per cent of drunk teenagers stopped by police had been given alcohol by their mother or father.

Many of those apprehended during a campaign against under age drinking in the resort last summer were 15 or 16 and had been allowed to go to Cornwall with friends to celebrate the end of their GCSEs.

Mr Sorek said: "We found that parents were dropping off their children with beer and alcopops - they were literally leaving them with a tent, sleeping bags, wellies and a crate of beer."

During the campaign, which followed the deaths of two teenagers, officers confiscated more than 6,000 bottles and cans of alcoholic drink. One group of four boys from Bristol arrived with more than 100 alcoholic drinks between them.

In one case a police community support officer rang the mother of one of four 16-year-old boys from Surrey who were caught with 64 cans of Special Brew.

"The mother had a go at my member of staff, saying, 'Haven't you ever had fun? You are stopping my son having fun, it's outrageous,'" said Supt Julie Whitmarsh, of Devon and Cornwall Police.

Another mother from the Home Counties, when told that her child had been behaving badly, dismissed the officer's concerns by saying: "My child is not the usual riff-raff."

On Wednesday Drinkaware will launch a new advice panel, "Mumtank", run by mothers with expertise in health and child psychology.

One of the members, GP Dr Sarah Jarvis, said: "While parents may be tempted to encourage children to try alcohol earlier rather than later, as a form of alcohol education, medical evidence shows that an alcohol-free childhood is best."

Last year an international study of almost 2,000 12- and 13-year-olds found that those whose parents allowed them an occasional supervised drink were more likely to abuse alcohol as they got older.

The study found that children whose parents took such an approach were more likely to have got into alcohol-related trouble- such as fights, blackouts, or not being able to stop drinking than those whose parents had a "zero-tolerance" strategy.

A separate Dutch study of 500 12-to-15-year-olds, found that it was the amount of alcohol available at home, and not how much parents drank, that determined teenage drinking habits - suggesting parents should keep their drinks cabinets locked.